Wicked!! My all time favourite (I saw it 6 times)
Phantom of the Opera (have seen it twice on stage (I own the movie) and listened to the soundtrack a million times)
Les Miserables (one of my favourite sound tracks. I've seen it once in London and have tickets for this coming November, plus own the movie. Another soundtrack I've listened to a million times)
Mary Poppins (I have the musical soundtrack, but love both stage and screen versions).
Dr Zhivago (the music in this is beautiful, I just wish there was an Australian Cast recording)
Sound of Music
I haven't seen it, but I have the soundtrack from The Secret Garden. It's quite enjoyable.
Anything with Anthony Warlow really!
Mamma Mia (my friends give me stick for this, but I love ABBA haha)
Chess (co written by Benny and Bjorn from ABBA)
Fame! I've seen about 3 different productions of it, it's great.
Jesus Christ Superstar (I missed seeing the recent version with Tim Minchin and Mel C as my pop died the day before I was supposed to go, but DH said it was awesome!)
Joseph and the Amazing Technicolor Dreamcoat (I was in a production of this at school so I'm a bit biased haha)
Cats is good when I'm in the mood for it
Rock of Ages (who doesn't love a bit of 80s)
Avenue Q!!!!! But you have to not be a person easily offended to enjoy this
I've also. Enjoyed some of the biographical ones I've seen like Dusty and The Boy From Oz.
I have an old Andrew Lloyd Webber CD lying around that had a mix of songs from his different musicals so every now and then a random song will pop up in my playlist haha.
ETA I forgot Jersey Boys! I listen to the soundtrack all the time!